Stand up staging.dmarc.mx + promote migrations through staging before prod

[schmug]

Why

Today every change — including D1 schema migrations — flies straight to prod via the Cloudflare Git integration. With Pro subscriptions about to go live (#185 unblocks), the cost of a broken migration goes from "Cory notices and fixes" to "paying customer sees an outage." The expand-contract migration discipline already in CLAUDE.md is good, but it's a convention, not a backstop.

This issue stands up a minimum-viable staging environment that costs ~$0/mo and adds ~30 min of one-time setup, then makes migrations land in staging before prod.

Out of scope: gradual / versioned rollouts (`wrangler versions deploy`) — that's a separate track for risky code changes, filed separately if/when needed. This issue is specifically about the schema safety net.

Scope

1. Cloudflare resources

• Create D1 database `dmarcheck-db-staging`
• Add DNS: `staging.dmarc.mx` → Worker (Cloudflare DNS, no extra cost)
• Create staging WorkOS environment (sandbox tier, free)
• Reuse existing Stripe test mode keys (no new account needed)
• Cloudflare Web Analytics: do NOT add a token for staging — keep beacon off there

2. `wrangler.toml`

Add an `[env.staging]` block:

```toml
[env.staging]
name = "dmarcheck-staging"
route = { pattern = "staging.dmarc.mx/*", zone_name = "dmarc.mx" }

[[env.staging.d1_databases]]
binding = "DB"
database_name = "dmarcheck-db-staging"
database_id = ""
```

Wrangler secrets to set on the staging env (separate from prod):

• `WORKOS_API_KEY` / `WORKOS_CLIENT_ID` (sandbox)
• `STRIPE_SECRET_KEY` / `STRIPE_WEBHOOK_SECRET` / `STRIPE_PRICE_ID_PRO` (test mode)
• `SESSION_SECRET` (different from prod — staging sessions must not be valid in prod)
• (No `CF_ANALYTICS_TOKEN` — keep beacon off staging)

3. Sentry

• Don't create a separate Sentry project — set `environment: "staging"` in the SDK init based on a build-time flag or a `STAGING=1` env var
• Optionally bump sample rate to 1.0 in staging (everything is interesting there)

4. Migration promotion workflow

Update `.github/workflows/migrate.yml` so the safe path is staging-first:

```
push to main
→ CI passes
→ migrate.yml runs:
step 1: wrangler d1 migrations apply dmarcheck-db-staging --remote
step 2: GET https://staging.dmarc.mx/health (must 200)
step 3: wait for manual approval (environments: prod)
step 4: wrangler d1 migrations apply dmarcheck-db --remote
```

Implementation notes:

• Use GitHub Environments with required reviewers on the `prod` environment for the approval gate. Cory is the only reviewer; one click promotes.
• Steps 1-2 run unattended; if step 2 fails, step 4 never runs and main stays partially deployed (which is fine because of the additive-only migration discipline already in CLAUDE.md).
• The Cloudflare Git integration deploys the code to prod independently — the migration workflow only gates the schema. Code-vs-schema ordering still relies on the existing additive-only discipline.

5. README + CLAUDE.md updates

• Add a "Staging" section under Database migrations describing the new flow
• Document that `staging.dmarc.mx` is a non-public testing surface (`noindex` enforced) and that anyone who finds it should not file issues against it
• Add a `<meta name="robots" content="noindex,nofollow">` injection on staging via an env-var check in `src/views/html.ts`

6. CI: deploy staging on every main commit

The Cloudflare Git integration currently deploys main → prod. Add a parallel auto-deploy for staging via either:

• A second connection in the Cloudflare dashboard targeting the `env.staging` config, or
• A GitHub Actions workflow that runs `wrangler deploy --env staging` on push to main (uses a Workers Edit token, scope-restricted)

The first option is lower-friction; the second gives us versioned-deploy headroom if we want `wrangler versions deploy` later.

Acceptance criteria

• `https://staging.dmarc.mx\` returns 200, serves the same UI as prod, with a visible "STAGING" banner (suggest: red ribbon top-of-page in `src/views/html.ts` keyed off env)
• `https://staging.dmarc.mx/api/check?domain=dmarc.mx\` returns the same shape as prod
• A test Stripe Checkout against staging completes end-to-end with a 4242 test card and unlocks Pro on the staging account
• A new migration PR demonstrates the gated flow: applies to staging → smoke passes → approval gate → applies to prod
• `robots.txt` and the `` tag both noindex staging
• Sentry events from staging arrive tagged `environment: staging`

Estimate

~30–45 min of one-time Cloudflare/WorkOS/GitHub config + ~50–80 lines across `wrangler.toml`, `migrate.yml`, `html.ts`, README, CLAUDE.md. Single PR.

Follow-ups (separate issues, not part of this)

• Versioned/gradual code rollouts via `wrangler versions deploy` for risky changes (scoring, billing, auth)
• Authenticated smoke tests against staging Pro routes (extends Add post-deploy prod smoke test workflow #190)
• Synthetic Stripe lifecycle test against the real Stripe test mode (extends End-to-end Stripe flow test (Checkout → webhook → Pro unlock → Portal cancel → downgrade) #191)

[schmug]

Postmortem: PR-A (#203) caused a ~30-minute outage on dmarc.mx (2026-04-26 ~19:05–19:35 UTC)

What happened

1. feat(staging): scaffold staging.dmarc.mx environment (PR-A of #195) #203 added [env.staging] to wrangler.toml with name = "dmarcheck-staging" and staging.dmarc.mx as the only Custom Domain in that block.
2. Cloudflare Workers Builds on this repo is bound to the prod dmarcheck worker. On the next push to main, Builds ran wrangler deploy --env staging against dmarcheck — Builds ignores the env-level name override and deploys to whichever worker the Builds connection is wired to.
3. That replaced the prod routes block with the staging routes block, detaching dmarc.mx as a Custom Domain. Cloudflare's auto-managed apex A record disappeared with the Custom Domain binding.
4. Symptoms: dig dmarc.mx A returned no answer, staging.dmarc.mx came up on the prod worker, Sentry quiet (no requests reaching the worker).
5. Cloudflare auto-PR Update name in Wrangler configuration file to match deployed Worker #204 ("the deployed Worker for the staging env is named dmarcheck, not dmarcheck-staging") was a real signal, not a misfire. It was closed without acting on the underlying mismatch.

Recovery

• Custom Domain dmarc.mx re-attached manually in the Cloudflare dashboard.
• revert(staging): back out #203 — Workers Builds clobbered prod dmarc.mx #206 reverted feat(staging): scaffold staging.dmarc.mx environment (PR-A of #195) #203 from main so the next auto-deploy can't re-clobber the binding.

Prerequisite before re-attempting staging

Workers Builds has to stop deploying [env.staging] against the prod worker. Two viable shapes:

Option A — separate Builds connection per worker. Spin up a second Cloudflare Workers Builds connection bound to a dmarcheck-staging worker, deploying only on a staging branch (or with a separate build command targeting the staging env). The prod Builds connection stays on bare wrangler deploy (no --env).

Option B — provision the staging worker out-of-band. Keep [env.staging] out of the shared wrangler.toml. Provision the staging worker once via wrangler deploy --env staging from a local checkout (or a sibling wrangler.staging.toml), and after that, deploy staging manually on a staging branch. The prod Builds command stays as wrangler deploy and never sees env-level config.

Either way: do not re-add [env.staging] to the shared wrangler.toml until the Builds wiring is verified to ignore it. A 5-line dry-run check (push to a throwaway branch, watch which worker deploys) catches this before it hits prod again.

Cleanup still needed

staging.dmarc.mx Custom Domain is orphaned (DNS still resolves; worker behind it returns 530 after the revert). Either re-attach it to a real dmarcheck-staging worker once that exists, or remove the Custom Domain from the zone.

[schmug]

Status update: this was attempted in #203 and reverted in #206. Adding [env.staging] to the shared wrangler.toml triggered a prod outage on dmarc.mx — Cloudflare Workers Builds is pinned to the prod worker (the top-level config), and the env block reshaped the deploy unexpectedly.

Future attempt should avoid [env.X] in the shared wrangler.toml. Likely options:

1. Separate wrangler.staging.toml + a parallel Workers Builds connection / GitHub Action for staging only. Keeps prod's Builds pin untouched.
2. Standalone staging worker (different name, different repo or branch trigger) rather than an env of the same worker.

Either way, validate the deploy plan against the constraint that prod's Workers Builds reads the top-level config and silently breaks if env blocks are introduced.

[schmug]

Operator actions required (cannot be done via code PR alone)

This issue splits into: operator-only setup, and code changes I can ship in a PR. Here's the breakdown:

Operator must do in Cloudflare/GitHub/WorkOS consoles (~30 min):

1. D1: Create dmarcheck-db-staging database in Cloudflare dashboard → copy its database_id
2. DNS: Add staging.dmarc.mx CNAME → Worker in Cloudflare DNS panel
3. Cloudflare Git Integration: Add a second connection targeting wrangler.toml's [env.staging] config (or wire via GitHub Actions)
4. Wrangler secrets: wrangler secret put --env staging for WORKOS_API_KEY, WORKOS_CLIENT_ID (WorkOS sandbox), STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET, STRIPE_PRICE_ID_PRO (Stripe test mode), SESSION_SECRET (unique value)
5. GitHub Environments: Create a prod environment in repo Settings → Environments, add yourself as required reviewer — this gates step 4 of migrate.yml
6. WorkOS: Create sandbox environment, note the client ID + API key

Code changes I can open a PR for right now:

• wrangler.toml: add [env.staging] block with route, D1 binding, vars
• .github/workflows/migrate.yml: add staging-first migration flow with health check + manual approval gate
• src/views/html.ts: inject <div class="staging-banner">STAGING</div> + noindex <meta> when env var STAGING=1 is set
• CLAUDE.md + README.md: document the staging flow

Want me to open that PR now so the code is ready to wire up once you complete the console steps? I'll leave the database_id as a placeholder for you to fill in.

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